1. Field
The present technology relates to a coupling structure for electrode tabs of a secondary battery and a secondary battery using the same.
2. Description of the Related Technology
A secondary battery is a device that converts chemical energy generated by an electrical reaction into electrical energy. Unlike primary batteries, secondary batteries are rechargeable and have high voltage and current density. Thus, secondary batteries are widely used in electric appliances such as portable terminals.
Among these secondary batteries, a lithium secondary battery basically has a structure in which electrode plates are stacked so as to secure a suitable output factor.
Specifically, in the state in which a plurality of negative electrode plates and a plurality of positive electrode plates are alternately stacked, positive and negative electrode tabs are extracted from the respective positive and negative electrode plates, and the positive or negative electrode tabs are also stacked with one another.
Since the positive or negative electrode tabs are simply stacked with one another but separated from one another, they are connected to one another through a separate process.
The connection between positive or negative electrode tabs is typically made using an ultrasonic welding method. However, a large-capacity battery has a large number of positive and negative electrode tabs, and is thick in thickness. Hence, when the positive or negative electrode tabs are connected using only the ultrasonic welding method, it can be difficult to obtain a suitable fastening force, and operational efficiency may be lowered due to a long welding time.
In order to solve such a problem, a riveting connection method has recently been proposed in which positive or negative electrode tabs are connected to one another by &liming through-holes on the same line in positive or negative electrode tabs, and then inserting a separate rivet into the through-holes.
However, in such a method, the through-holes typically must be formed individually in each of the positive or negative electrode tabs. Therefore, the operation of the method can be inconvenient and the operational time can be increased.